1. Field of the Invention
The present invention relates generally to medical methods and apparatus. More particularly, the present invention relates to methods and systems for controlling the deployment of needles using treatment and safety boundaries projected onto an image of tissue to be treated.
Current medical treatments of organs and tissues within a patient's body often use a needle or other elongate body for delivery of energy, therapeutic agents or the like. Optionally the methods use ultrasound imaging to observe and identify a treatment target and track the position of the needle relative to the treatment target.
Of particular interest to the present invention, a treatment for uterine fibroids has recently been proposed which relies on the transvaginal or laparoscopic positioning of a treatment device in the patient's uterus. A radiofrequency or other energy or therapeutic delivery needle is deployed from the device into the fibroid, and energy and/or therapeutic substances are delivered in order to ablate or treat the fibroid. To facilitate locating the fibroids and positioning the needles within the fibroids, the device includes an ultrasonic imaging array with an adjustable field of view in a generally forward or lateral direction relative to an axial shaft which carries the needle. The needle is advanced from the shaft and across the field of view so that the needle can be visualized and directed into the tissue and the targeted fibroid.
While effective and very beneficial for patients, such needle ablation and treatment protocols face several challenges. First, initial deployment of the needle can be difficult, particularly for physicians who have less experience. While the physician can view the tissue and target anatomy in real time on an imaging screen, it can be difficult to precisely predict the path the needle will take and assess its final treatment position. While the needle can certainly be partially or fully retracted and redeployed, it would be advantageous to minimize the number of deployments required before treatment is effected.
A second challenge comes after the needle has been deployed. While the position of the needle can be observed on the ultrasonic or other visual image, the treatment volume resulting from energy or other therapeutic delivery can be difficult to predict. As with initial positioning, experience will help but it would be desirable to reduce the need to exercise judgment and conjecture.
A third challenge lies in assuring that nearby sensitive tissue structures, such as the serosa surrounding the myometrium, are not unintentionally damaged. As with judging the treatment volume, predicting the safety margin of the treatment can be difficult.
U.S. Pat. No. 8,088,072, commonly assigned with the present application, describes a system for projecting safety and treatment boundaries on a real time image of the fibroid or other tissue structure to be treated. While very effective when used with single needles, the system of the '072 patent is not optimized for use with multiple needle/tine assemblies, such as those taught in commonly owned U.S. Pat. Nos. 8,206,300 and 8,262,574.
For these reasons, it would be desirable to provide improved systems and methods for the deployment of energy delivery and other needles within ultrasonic or other imaging fields of view in energy delivery or other therapeutic protocols. It would be particularly useful to provide the treating physician with information which would assist in initial deployment of a plurality of needles or tines in order to improve the likelihood that the needle assembly will be properly positioned relative to a targeted anatomy to be treated. It would also be desirable to provide feedback to the physician to assist in accurately predicting a treatment volume. Such information should allow the physician, if necessary, to reposition the probe in order to increase the likelihood of fully treating the anatomy. Furthermore, it would be desirable to provide feedback to the physician allowing the physician to assess a safety margin so that sensitive tissue structures are not damaged. All such feedback or other information are preferably provided visually on the ultrasonic or other imaging screen so that the needle position can be quickly predicted, assessed, and treatment initiated. It would be further desirable if the feedback information were presented on a display screen in response to manipulating the probe while minimizing the need to enter data or commands onto a system controller or display, and still further desirable if such manipulation of the probe could set stops or other limits which controlled the extent of subsequent needle deployment. At least some of these objectives will be met by the inventions described hereinafter.
2. Description of the Background Art
U.S. Pat. Nos. 8,088,072; 8,206,300 and 8,262,574 have been described above and are incorporated herein by reference. U.S. Pat. No. 7,918,795, commonly assigned with the present application, describes probes useful for both imaging and treating uterine fibroids, which probes could be used in the systems and methods of the present application and is incorporated herein by reference. Other commonly assigned patents and published applications describing probes useful for treating uterine fibroids in the systems include U.S. Pat. Nos. 7,874,986 and 7,815,571; and U.S. Patent Publications 2007/0179380 and 2008/0033493. See also U.S. Pat. No. 6,050,992 and U.S. patent Publication 2007/0006215.